Last time I was there (just before midnight mid June) I noticed a new path that seemed to head up and round it, but I didn't take because it was dark and I was familiar with the old route. Now I'm wondering if they were on that path, cresting on side of the gorge, rather than going thru' the middle???
This is all speculation at the moment, but some of the reports have mentioned casualties being on BOTH sides of the gap at the time of the avalanche. Photographs show snow slabs piled up at the bottom of the gap.
I agree with your description of the Chalamain Gap. Some here will recognise it as a handy route between the Rothiemurchus Hut and the high tops.